msp430例程 msp430例程

//----------------------------------------------------------------------------- // MSP-FET430P140 Demo - I2C, Slave TMP100 Emulation II // // Description: Uses ADC12 and I2C modules to emulate behaviour of the TMP100 // temperature sensor. // // //* An external 32kHz watch crystal on XIN XOUT is required *// // // - DMA services I2C module (transmit and receive) // - Timer_A triggers ADC12 temperature conversion every 1/10s // // +--------------------+ // | | // | | // | | // | P3.1 +<------> I2C SDA // | P3.3 +<------- I2C SCL // | MSP430F169 | // | | // | | // | | // | | // | | // +--------------------+ // // // A. Dannenberg // Texas Instruments Inc. // Feb 2005 // Built with IAR Embedded Workbench Version: 3.21A //----------------------------------------------------------------------------- #include <msp430x16x.h> //----------------------------------------------------------------------------- #define TMPADDR 0x4E // TMP100 Slave Address with // A0=A1=A2=1 void Init_Sys(void); // Function prototype static unsigned int ADCResult; // Holds the last ADC result static unsigned int CurrentTmp; // Holds current temperature // to be transmitted static unsigned int ReceivedWord; // //----------------------------------------------------------------------------- // ADC12 Module Temperature Table // // These values assume nominal values for the temp diode and // temperature coefficient. They also assume the 2.5V internal // reference is used for the conversion. The transfer function out // of Figure 17-10 of the MSP430x1xx Family User's Guide (SLAU049C) // has been used. //----------------------------------------------------------------------------- static const unsigned int Temp_Tab[] = { 0x064F, // 0C 0x0655, 0x065B, 0x0660, 0x0666, 0x066C, // 5C 0x0672, 0x0678, 0x067D, 0x0683, 0x0689, // 10C 0x068F, 0x0695, 0x069B, 0x06A0, 0x06A6, // 15C 0x06AC, 0x06B2, 0x06B8, 0x06BD, 0x06C3, // 20C 0x06C9, 0x06CF, 0x06D5, 0x06DB, 0x06E0, // 25C 0x06E6, 0x06EC, 0x06F2, 0x06F8, 0x06FD, // 30C 0x0703, 0x0709, 0x070F, 0x0715, 0x071B, // 35C 0x0720, 0x0726, 0x072C, 0x0732, 0x0738, // 40C 0x073D, 0x0743, 0x0749, 0x074F, 0x0755, // 45C 0x0FFF // Too high }; //----------------------------------------------------------------------------- void main(void) { unsigned int i; Init_Sys(); // Initialize system _EINT(); // Enable interrupts while (1) // Repeat forever { _BIS_SR(LPM3_bits); // Wait for ADC conversion // completion for (i = 0; i < sizeof Temp_Tab; i++) // Get temperature value out if (ADCResult < Temp_Tab[i]) // of table break; _DINT(); // Protect next statement CurrentTmp = i; // Save current temperature _EINT(); } } //----------------------------------------------------------------------------- // setup system and peripherals //----------------------------------------------------------------------------- void Init_Sys(void) { WDTCTL = WDTPW + WDTHOLD; // Stop watchdog timer BCSCTL1 = XT2OFF + RSEL2 + RSEL0; // Adjust DCO frequ // D169 specific initialisation P1OUT = 0x10; // Disable audio output stage P1DIR = 0x3f; // P1.6/P1.7 inp, all other outp P2OUT = 0x00; // Clear P2 output register P2DIR = 0xff; // Unused pins as outp P3SEL = 0x0a; // Assign I2C pins to module P3OUT = 0x00; // Clear P3 output register P3DIR = 0xff; // Unused pins as outp P4OUT = 0x00; // Clear P4 output register P4DIR = 0xff; // Unused pins as outp P5OUT = 0x00; // Clear P5 output register P5DIR = 0xff; // Unused pins as outp P6OUT = 0x00; // Clear P6 output register P6DIR = 0xfe; // Unused pins as outp // Setup I2C module U0CTL |= I2C + SYNC; // Switch USART0 to I2C mode U0CTL &= ~I2CEN; U0CTL |= RXDMAEN + TXDMAEN; // Enable I2C DMA triggers I2COA = TMPADDR; // Own address = TMP100 device addr I2CTCTL = I2CWORD + I2CSSEL1; // Select SMCLK, word mode U0CTL |= I2CEN; // Enable I2C module, 7 bit addr, // Slave mode // Setup DMA DMACTL0 = DMA0TSEL2 + DMA1TSEL1 + DMA1TSEL0; // I2C transmit ready -> DMA0 // I2C receive ready -> DMA1 DMA0SA = (int)&CurrentTmp; DMA0DA = I2CDRW_; DMA0CTL = DMADT2 + DMAEN; // Repeated single transfer DMA1SA = I2CDRW_; DMA1DA = (int)&ReceivedWord; DMA1CTL = DMADT2 + DMAEN; // Repeated single transfer // Setup Timer_A CCR0 = 3277; // 1/10s w/ 32kHz ACLK CCR1 = 3276; // ADC12 start-of-conversion TACCTL1 = OUTMOD_3; // set on EQU1, reset on EQU0 TACTL = TASSEL_1 + MC0; // ACLK, start timer in up-mode // Setup ADC12 ADC12CTL0 = ADC12ON + REFON + REF2_5V + SHT0_6;// Turn on ADC12, 2.5Vref, set SHT0 // for longer sampling required by // temp diode. ADC12CTL1 = SHS_1 + SHP + CONSEQ_2; // Use sampling timer, Timer_A.OUT1 // triggers conversion, rep. single // channel ADC12MCTL0 = INCH_10 + SREF_1; // Select channel A10, Vref+ ADC12IE = 0x01; // enable ADC12IFG.0 for ADC12MEM0 ADC12CTL0 |= ENC; // Enable conversions } //----------------------------------------------------------------------------- // Interrupt Service Routine for ADC12 //----------------------------------------------------------------------------- #pragma vector=ADC_VECTOR __interrupt void ADC12ISR(void) { ADCResult = ADC12MEM0; // Move result, IFG is cleared _BIC_SR_IRQ(LPM3_bits); // Return active }